I discovered the original Wolfenstein, downloaded it off a BBS, before I had ever heard of Doom. Most consider Doom to be first, but in the circle I ran in back in the day, Wolfenstein was widely used way before Doom.
The problem is Wolfenstein and Doom both were projects of passion, not commercial products. So, releases were posted and shared in real time and it was quite awhile before a proper commercial-like "official version 1.0" was formally released. This is true for a ton of game changing programs, games, and online services back in the early days before the World Wide Web. many of the most innovative and successful were just being made because someone thought it would be cool and they just let everyone have it, for free, and wanted to hear feedback so they could improve the software. Fun times! But it makes creating an accurate history difficult.